To be fair, MC had no recollection of ML. It’s understandable why ML would be clingy towards MC but it is also understandable why MC would be uncomfortable at first cause he doesn’t remember ML.
Luckily MC grew fond of ML even if he couldn’t remember their past together. Now that he does remember, all the more reason he’ll be even more affectionate with ML. It’s even more normal that ML is ecstatic that MC finally remembers him. (2 years away and 1 year with a man who couldn’t remember their relationship takes a toll.)
They could do with more conversing rather than just straight sex but other than that they are fine for now.

Do people not act clingy if they didn't get see their lover for the past 3 years? Like isn't that a normal thing couples do?