#28223
You deal with it by realizing that we all, at one time or other, lust in our hearts. Just because you're in a relationship with someone, it doesn't mean that you stop noticing good looking people. That's OK. It becomes a problem when a person acts on the fantasy and cheats. That's not OK. If the guy is with you and is faithful---no problem.
If you are still in the relationship with the guy who brought 2 girls back to your apartment when he got drunk, then I think you do have reason to worry everytime he looks at another woman. You have a child with another one on the way and this guy you're with isn't the baby daddy. Right now, you should be putting your kids first and that means giving them the most stable home life you can. If that means you dump the guy (which it should mean) then so be it.