There is also one alternative that I failed to mention - and I find this to be very popular in jealousy situations:

Are you sure you are not the one who has been looking around, playing games with other women (flirting, etc.)? Because oftentimes, and especially in cases of jealousy, it is the person who is doing the accusing that is actually the one doing the fooling around...

If you are, you are simply projecting your suspicious behaviour onto her.