I have never seen
Teen Titans (2003-2006, 2012-), the cartoon series based on the DC comic books, so I don't know much about the shapeshifting Beast Boy. But according to Wikipedia, he is portrayed as a lighthearted jokester (voiced by Greg Cipes, left). He is best friends with Cyborg, and has a love-hate romance going on with a female titan named Raven.
In the live action
Titans, he's portrayed by Ryan Potter, who is bisexual in real life, so maybe he's got some bi subtexts going on.
In the comics, Beast Boy interacts with Jimmy Olsen when he's transformed into a giant turtle, but fan artist usually limit Beast Boy's same-sex loves to Robin and Aqualad.
Robin gets more s*xual acts, sometimes unwillingly. Here they're being pushed together and assaulted by purple tentacles (a Japanese tradition).
Fan artists like envisioning Beast Boy and Robin in intimate situations. This is about as G-rated as their pairings get.
More after the break
For more romantic relationships, Beast Boy is usually paired with Aqualad, who appeared in the first season as his rival (another pair of antagonists in love).
Even while he's in love, Beast Boy's irreverent, fun-loving nature shines throughout. Here, dressed up for the Old West, he makes a risque joke about "poking dogies," while embarrassed boyfriend Aqualad, asks him to put on pants under his chaps (so his bare backside doesn't show).
(Original pictures from the artists on deviantart.com.)
