DEAR DEIDRE: MY company sent me on a bonding weekend - and it I bonded very well with one colleague in particular.

I had a wild night with a woman who does the same job as me in a different branch. Should I tell my fiancée?

I'm 26 and have been in my job for a year. We work from home, so a month ago the company arranged a weekend away to help us get to know each other.

When I arrived at the hotel, I immediately spotted a stunning woman in reception. She was slim, petite, toned and blonde -- the type I always went for until I met my curvy brunette fiancée.

This woman is my age and we had a lot in common -- we're into the same bands for a start.

We spent most of that first evening talking about work. She was bubbly and fun but I went to bed early and had a long phone call with my fiancée.

The next evening was a different story. We spent the day doing team-building exercises. I was on the same team as this woman. As we bonded over archery, she pushed her body close to mine.

That evening, the company had laid on a free bar.

I woke up the next day feeling fantastic. By 11pm, I was tipsy and flirting with this woman. By midnight we were in my room, having wild sex.

But when I saw my fiancée waiting for me at the station, I immediately felt sick.

Now the guilt has receded, I'm starting to compare our humdrum sex life -- and my fiancee's appearance -- with the incredible night I had with my colleague.

Do I take this as a sign my marriage is already doomed?

DEIDRE SAYS: Do not rush into this wedding. You may have simply got caught up in the moment on the work weekend, or the alcohol lowered your inhibitions.

But there's also a chance that your fiancée simply isn't the right woman for you.

I don't believe affairs are always a sign there's something wrong in a relationship but they can indicate that further scrutiny is advisable.

Your repeated comments about your fiancée's appearance suggest the physical attraction may not be very strong.

Friendship alone isn't enough for a successful marriage - you need to have sexual chemistry too.

You could confess all and let your fiancée choose whether you split or commit. But it is worth exploring your own feelings first.

My support pack, Can't Be Faithful? explains why some people are drawn to cheating, and how to understand your feelings about your relationship.

Counselling would also help you gain more insight.

DEAR DEIDRE: I'M worried my girlfriend's bitter, jealous friend will ruin my proposal.

My girlfriend is the best woman I've ever met. I fell in love with her the minute I saw her dating profile online.

In the six months we've been together, I've only discovered more things to adore. I want us to spend the rest of our lives together.

We're both 28 and I've just booked a romantic week-long holiday in Dubai for the two of us. My plan is to propose to her on the stroke of midnight on New Year's Eve.

However, my girlfriend's best pal is poisonous. Even though she's conventionally pretty, she has an ugly personality. Men never hang around for long.

I suspect she has tried to split us up in the past. She started rumours about me seeing other women - but I wouldn't do that.

And she is always rolling her eyes when I'm around. My girlfriend is excited about our holiday.

I obviously haven't let on about my plan to propose. I've bought a ring and have written a poem to read out when I ask her to be my wife.

I was counting the days until we left. But her friend has just been dumped yet again, and now my girlfriend wants to invite her along on our trip to cheer her up.

I really don't want that toxic woman anywhere near my proposal. I know what she's like - she'll laugh at my poem, criticise the ring and probably put doubts into my girl's mind.

If I tell my girlfriend that her heartbroken friend can't join us, I'll look like the bad guy. But if I let her join us on the holiday, she might ruin it. What should I do?

DEIDRE SAYS: This "friend" probably feels threatened by your relationship.

If she's used to having your girlfriend all to herself, she could worry your presence will limit the time they spend together, or that you'll influence your girlfriend into dumping her.

With a history of failed relationships, this friend could well have abandonment issues and feel insecure.

But that's no reason to let her join you on your once-in-a-lifetime holiday.

Tell your girlfriend that you're sorry her friend is upset, but you really want this trip to be for the pair of you. But arrange an evening out for the three of you where you can show your support.

When this friend realises you're not trying to end their friendship, she may relax.

DEAR DEIDRE: TO recuperate after an operation, my sister has moved back in with me and our mum.

I'm happy to help look after her but she brought her husband too, and now she thinks I'm lusting after him.

I'm 24, my sister is 28 and her husband is 30. He's nice, but shy and quiet, possibly because my sister nags and puts him down.

I can't stand bullies, so I stand up for him. That has convinced my sister I'm plotting to take her man.

The atmosphere at home is toxic but I can't afford to move. What should I do?

DEIDRE SAYS: Focus on getting your sister on her feet so she can walk back out of the house.

If tensions are running high at certain times - like shared mealtimes - avoid those as much as you can.

Try getting up earlier so you enjoy a couple of hours of peace before the drama begins.

You can find more help through Family Action (family-action.org.uk, 0808 802 6666, text line 07537 404 282). They provide a listening ear for any kind of family issue.