/ic/ - Artwork/Critique

How to deal with commissioner wanting to be friends or more? This person is blowing up my dms. Because they contacted me through irl social media I have to remain friendly business professional and cannot cause a scene - they wanted a book cover for their indie published project. I was friendly before they got me the commission information, but after that they crossed the line and started hitting on me - I shut that down immediately and let them know I have a partner which they respected and that has ceased... Work for the commission doesn't start till many months from now, but still they are messaging me every other day asking how I am, it's too much!! I toned down the friendliness and now take multiple days to reply, but I feel I cannot completely block them due to professionalism. What do?