My brotherís wife was someone who was very kind, very helpful, and sometimes a little too close. She always invited people over and I thought it always weird she was inviting my brotherís friends and no girls to her husbandís birthday parties, kidís birthdays, her birthday, and even her in-laws. I appreciated the invite and somehow I knew about them all the time because we have a big family and weíre all close, so I came over with my brother and their kids. We are there and having a good time when I notice she was talking to the other guys and just making really good eye contact. Then, she starts with crisscrossing her legs back and forth in short shorts, and he is wearing a tight t-shirt. He is arm gesturing and having incidental contact of their arms. Iím thinking its okay, just regular in-law touching. Iím looking for her husband, who was nowhere to be seen. Maybe he was busy with gifts or something. Meanwhile, I am under a tent/cover from the sun and all of a sudden, I see their feet touching each other once in a while, plus getting their phones out; getting each otherís numbers for further conversation in the future. No big deal, but they donít stop and soon here comes her husband out of the house with food and presents. They both help with the presents and food. Then, I notice she is on her phone again texting so I look over at him and he is with his phone too; theyíre glancing at each other so often and sheís helping with the birthday stuff. About thirty to forty-five minutes go by and theyíre glancing at each other still. Iím assuming theyíre both texting each other, maybe something is wrong, she needs more help or something; but nope, she bends over at him and he just stares at her. Iím like, "Oh man." There isnít anything wrong, she is just flirting with him and giving a show for now. A couple of hours go by, people are cleaning up, and she does clean up for a good thirty minutes as well. Then, she just disappears and he is not in sight. Me, being curious, went to go look to go see if their cars are there, and nope theyíre gone. So, Iím waiting looking like Iím doing something and her husband is wondering where she is and if anybody has seen her. It was about an hour maybe at the most, and no sign of her. Her husband is texting her asking where she is and she said she went to go get some ice or something. He comes back first and makes sure stuff is in his car that he brought and so forth, then she comes rolling in. Later on that day, her husband doesnít see anything wrong and leaves to go help someone. He stays to help her with the kids. Later on, at night he helps with the kids and theyíre both on their phones. Iím here too in case he had to leave. Iím just sitting; when they are not in sight, I go upstairs and snoop. Theyíre both hugging and touching each other and putting her kids to bed when I catch something unusual, she is wearing a tank top with no bra and theyíre hugging. I am looking in just enough to see what was going on and Iím scared. For an eighteen-year-old, I am afraid I will get caught. I walked back downstairs and pretended nothing happened, but theyíre up there for a good hour or two. I donít know if I should I be concerned enough to tell my brother, or wait to see more evidence.