Hello Life In Virtual.
It sounds like your male peep "thinks" the path to the side of the bed that he likes is obstructed by something (usually a decor object). Since he can't make it to the bed, he's choosing an activity that he can accomplish. For tips on how to fix it, see Section A #2 in
Helpful VF2 Windows/Mac Tips & Answers.
There are other factors that can affect whether or not a couple is successful in making a baby: Health, desire to have children, etc. Just as in real life, not all attempts at babymaking will produce a child. If you're worried and can afford it, purchasing a Doctor Consultation and using it on 1 of your peeps will let you know whether or not that peep could use a dose of Baby Boost (sometimes I buy 2 Doctor Consultations and use one on each peep). Good Luck!