is it still considered cheating if they didn’t date(read des⬇️)

okay so i had a bestfriend who we’ll name alyssa and a gf who we’ll name lily. Me and lily were dating, but whenever me and lily had little “breaks” from eachother she would kiss & give hickeys to alyssa. I consider that as cheating, bc I even asked both of them to stop talking since they had kissed in October but didn’t tell me until December. They both deny and don’t own upto shit 😂 (even though I have ss from THEIR friends dming me and telling me 💀.) they stay posting about loyalty but do you guys consider this as cheating ?