Can a married man really love his mistress?

have a friend who is with a married man and has been for over a year. The guy claims that he is going to leave his wife however about 2 month's ago he bought a house and truck with his WIFE. I keep telling her that he will never leave her because he has to much to lose. About a week ago this same guy hit on and tried to take things further I 1st and foremost told him no because he is married and my bff is his girlfriend also. So what my question is......Is this guy really in love with my friend for is he just using her for ? Can he really love her and go home to his wife everynight and then hit on me?