Selena Gomez and The Weeknd are becoming the queen and king of dating on the down-low. The pair haven't even publicly confirmed their relationship, though they're clearly quite smitten. The low-key couple continued their mysterious ways during The Weeknd's (a.k.a. Abel Tesfaye) birthday this week. The singer turned 27 on Thursday. His 24-year-old girlfriend reportedly picked up the hefty $30,000 tab for his birthday party at Dave & Buster's in Los Angeles on Monday. (Gomez couldn't actually attend because she's on the East Coast for New York Fashion Week.) Then, today, the birthday boy posted a photo to Instagram to commemorate his special day (and the kick-off of his new tour). "27 Celebrating all year and partying every night all over the world starting with Sweden," he captioned the pic. "Let's fucking get it XO." Gomez responded with a telling double-tap. Yep, she liked the post. How very Selknd of her.