Help: In Love With My Sister In Law!

I’m happily married to a beautiful woman for four years. We have no kids yet. My wife’s sister is twenty-one years old and is a stunning beauty! She has the perfect taut body and a beautiful, cute face. Now, she being the baby of the family, is always hugged and kissed by everyone including my wife and me. She used to playfully flirt with me and I flirted back in front of my wife. Anyway, it’s been more than a year since I’ve seen her in person now, but she keeps sending sexy pictures of herself in short skirts, hot pants, etc. with friends. Till now, my wife has no idea that I secretly lust after her. I am about to meet her again in the next few months, and I fear I may not be able to control my feelings. My wife might find out, and then all hell will break loose! -Please What Should I do?

Kayefi