I think my Dad is cheating on my mom...

Im feeling very uncomfortable even having this thought, and more so sharing it online, i really hope that this is not the case but well I'll just tell you why i think this way. Firstly recently he has been very ungrateful towards him, we went to his friends house and someone told him "what a great wife you have" and he jockingly said "kya great yaar bhot sunna padta hai" he was laughing while saying this, i wouldn't have thought much but it has been happening a lot lately, and a few days ago my mother went to a wedding in her town and hasn't returned yet, my sister says ticket book karo kal but he said parso or smt, i felt uncomfortable for some reason. And today i asked him that didi is making omelet and he said ok , i told him come early he said he'll try but he came late saying that 'kaam tha' even after he came home he hasn't eaten the omelet, he said he's going out to eat with his friends but he has never went out this late before, only a few times. Also he has been coming home very late as well... i might just be paranoid and overthinking it but im just scared, i can't face it if it's the truth, and i really care about my dad...