A lie is a false statement made for either the speaker's advantage or the listener's disadvantage.

He would be lying if he only said it to get laid. It wouldn't be a lie if he said it to make you feel good about yourself or simply to be respectful to his wife. Apparently he doesn't realize that by demeaning his wife he's also demeaning himself.

I was raised to be a Christian (it didn't take very well), and taught that it's not Christian to say things that hurt people. Be aware that there are men out there who try to control their wives by beating down their self-esteem. You might be wise to seek marital or individual counseling.