My brother has been with his girlfriend for almost 8 years. She's an ok person. But I think my brother is on the verge of cheating on her. This started when we all went out to eat and our server who was a guy was clearly flirting with him. IDK if his girlfriend didn't notice or thought it was funny or what but when the server asked if he was single he did say no and point to his girlfriend and say they have been together for 8 years. The server said "8 years and no ring". Then laughed and said he was kidding. My husband*close friends with my brother* told me my brother added that server on Facebook. I talk to my brother about it and he said it's nothing bad. But when he was over our house and was texting this guy, I leaned over to look at the texts and my brother was telling him he thought his tongue ring was hot and he asked my brother would he like to feel it and sent a picture of him sticking his tongue out. I told him that ain't innocent and he told me he's not taking it seriously and is joke flirting. But I feel like my brother is getting more and more curious. I think it's wrong to stay in a relationship with a girl who wants to get married if he's tempting at this. He's my brother and I love him but he's opening a Pandora's box