Brother in law nude pics

So hear me out. My brother in law is supposedly straight. He asks for help every now and then as being a young 21yr old he has been forced to be on couches since his mom left the state (he stayed with his uncle then). She isn't a deadbeat she just knows he's an adult and should do for himself but time to time has helped him out.I married his brother. We are a gay couple early 20s. Been together 5 years. His brother has been always super attractive. I got jealous of his exes to experience such a nice guy. Don't get me wrong my husband is wonderful I wouldn't trade him for the world. We have some WHAT of an open relationship but still monogamous. We've joked about 3 some or someone pounding him or I while the other watches. Etc. anywho. His brother recently asked for money, which if I can do it I gladly help I don't care. But yesterday he asked for help to get groceries I didn't answer back because I was in the middle of sending it, all of a sudden, he sends 2 nude pics and promises to send me a video of him cumming today if I sent him money. As a gay guy who's been awkwardly attracted to his brother in law I got mixed emotions... I've always wondered what it looked like. But didn't really expect to ever see it. I never told my husband as he has a close relationship with his brother and they hang out a lot. I saw the photos and immediately got a hardon... like an intense I need to do something type hardon. I pleasured myself to the photos... now i feel bad but don't know if I should. My husband and I don't consider those types of things technically cheating. But, I'm having a feeling of falling for his brother as well. Recently I even dreamt about them getting sexual then me getting in the middle. But idk... is he gay? Bi? What? How do I do this? What do I do?