A person who is single on valentine's day and complains about it on twitter all day. They often claim that valentine's day is just a way for chocolate and greeting card companies to get money, not knowing that the practice has been around for 600 years. Because of their attitude, they will remain single the rest of their lives.
J: so how's it going for k?
B: not well, he's posting stuff about how valentine's day is a Hallmark holiday because he's single.
J: sounds like a Valentine's day denier.