Relationship advice For Friend

I’m very knew to this so please do not judge me or my friend, I’d appreciate it a lot. So my friend has been dating this girl for around 7 months, two months ago he cheated on her and sent an shirtless abs pic to a random girl and his girlfriend cried and cried and was a mess, recently she has been getting better and they’ve been happy and he told me that he hung out with one of his friend who is a girl, he said they cuddled and held hands and did things that a person in a relationship shouldn’t do... he said he cares about her a lot and she makes him extremely happy but is scared because he thinks he might not fall in love with her and she might. what’s something I can tell him or provide for him? Thanks.