There are four ways in which you can handle this:
- You can say nothing, and let it poison your feelings for him as well as any chance at an honest relationship.
Not recommended unless you have very low self-esteem and are not interested in raising it.
- You can yell at him the next time he turns to look at an attractive woman.
ONLY Recommended if he's mostly deaf or you don't intend to stay together much longer anyway.
You can point out his bad habit in an obnoxious way. For instance, the next time he turns to look at an attractive woman, run over and stand in the way. Bat your eyes or strike a seductive pose. Or compare notes with him: Say "Wow, check out that one!" Or loudly comment on the next attractive guy that passes.
ONLY recommended if he will actually get the hint. this could possibly backfire into making him see you as a kindred spirit in his skirt-watching. also, it is very important not to sound bitter when using this method.
- Calmly mention to him that this habit upsets you and that you'd like to discuss it.
Have you guessed yet that this is the choice i recommend? any partner worth keeping will be willing to discuss with you anything in the relationship that makes you unhappy. he may think you're completely wrong to feel this way, but if he's an adult, he can express this in a rational manner.
If it Bothers You, Tell Him
You don't have to agree on everything, nor should you expect him to change. However, there is nothing to be gained by keeping quiet on something that upsets you this much. if it's important enough to tell us, it's important enough to tell him.
I wish you luck. What I am proposing is probably the hardest thing to do in a relationship...and also the most important.