Hello there... my problem is that... we are a married couple with a young baby ( 1 year old this month) and I had to go to work at nights( 2 weeks after the baby`s birth) in order to support my family. My husband was busy as well, working on the farm, so we got one of our friends to babysit for us from time to time. It probably happened about 10- 15 times, otherwise my husband will stay with the baby. So it happened... one night they slept together and I found it out that night when I came from work. She is married as well, and her daughter was due to move in with us. I sort of thought, lets forgive them, and let the daughter move in with us( as she was meant to) as she was to start at college ( closer to our house). The mum said she was extremely sorry , which I doubted, since I have founded out that he was texting her about 10-15 text message. A day and talking on the phone.( I expect she was texting him back, as he wouldn't have gone on and on without a sign of aproval) she even gave him some porno tapes which I have found it later in the house( they were obviously not for me to boost my sexual life). Now the daughter lives with us and she`s doing my head in. I`ve even got her mum`s pic on the my computer( like I would want to see her!! ). And my husbands drives her there and there and everywhere, while I stay with the baby . Today I was off work, so I`ve done my gardening, fed all my animals, stayed with the baby, cooked for about 3 hours, and then they both ate... I didn't feel like eating... they left the plates and all the pANS for me to clean... and off to the pub, both of them... my husband and her daughter. I don't think its something between them now, but it hurts a great deal and he says I`m mental... he says its all in my head.. I just feel that with the daughter being here my marriage is going to end up shortly. We probably have an argument every day, and truly I feel like the maid in the house... the daughter has never washed a cup or at least putting it in the diswasher, nor put her rubbish in the bin. I don't feel like talking, nor screaming, I just feel like throwing her out and tell the husband to destroy her marriage the way she distroyed mine. I wouldn't call it revenge, I do think he deserves to know. Why can't the daughter stay with her mum? She just goes to college 3 days a week, and mum`s got 2 days off a week and the father three. Why do I have to ruin my marriage??

Wait... why exactly is this girl living with you? And is the baby yours?

Yes, the baby is ours( mine and my husband`s) and the girl is living with us as the college is a bit closer to our house than hers and my husband being a farmer, had decided that he has the time to drive her to school and back, as he doesn't work for an institution or office to be there in time.

If this girl is coming between your relationship she needs to go. You should be at the top of his list second ONLY to God. You have the right, as his wife and as a leader in your household to demand that either things change, or the girl goes. Maybe you could suggest that you take her to school instead.
Note: men tend to respond to women a lot better when women demand in an 'asking' tone. Its weird. But if he says asolutely not when you bring the matter to him calmly, you need to get him to evaluate and prioritize the marriage he is in.