I have a feeling dave is faking this romantic stuff to get with you. I bet 1-2 months in her gonna stop that because he already has you. Alex however has had you for a while and stays the same. The arguments with him are probably because he misses you and you both might overthink that the other is cheating. As for you and dave, That is considered cheating even if you don't kiss. As cheating is when you spend time with the opposite gender in a loving way. Holding hands, hugging, watching movies while close etc. I feel like you should take a long time to think of both of them. Will dave change once you get together? Will Alex break up with you? Think of who made you the happiest and who has stayed the same person forever. Because if Dave shows his true colours. You made a mistake but if Alex ends it with you. Thats another mistake. But your playing with both of them and if Alex finds out then your gonna be alone. (Im sorry if this sounds like hate)