I’m so stressed boyfriend cheated on me but is denying it?

Guys I’m so stressed out my boyfriend cheated on me but is denying it he went to a party a while back earlier last year and it has only come to light recently of him in a video with another girl stroking her face and dancing wit her. He’s admitted it’s him in the video and it’s someone who he used to be dating but he’s insisted we wasn’t together then. I’ve checked the videos out and he’s wearing the same clothes on the same date the party was earlier last year but he’s saying it’s from the year before and their releasing old videos for promotion but in the video he’s wearing the same clothes and so are the other people from last year In February when the party was when we was together. Not everyone will be wearing the same clothes to the party again?

don’t know if I should believe him honestly really really disheartened at this situation because it just goes to show he’s been lying or I don’t know if he’s telling the truth can someone help me out I have no idea what to do or who to talk to

I’m so stressed boyfriend cheated on me but is denying it?
Post Opinion