I don’t think this guy is normally a knight. I think he is wearing the armor specifically to repel arrows to avoid falling in love. He is on a “nothing serious” date and has already successfully repelled one arrow with his suit.
He knows that for him, falling in love inevitably leads to marriage, which inevitably leads to divorce.
When I saw this cartoon this morning, I didn’t notice the bent arrow on the table, which makes it slightly funnier for me.