The official info about the game changed a long time ago. It says MC is a young adult (his age isn't specified anymore), then the time he was away also changed to an uncertain time but more than 5 years.
In the game, MC mentions he is 18 before he meets Iris. Also the time Iris and MC are together has been changed and I might make a slight adjustment in the script since I'm redoing it anyway. I'm not gonna say how long they've been together, just saying it has been a while. so it's up to the reader to interpret however they like.
I was already in contact with Patreon, they know about the scene, they played the scene and told me it's fine and there's no need to change anything. No rules are being broken.