Yes, he is. Bumblebee does fall in love with Arcee in Transformers vs. G.I. Joe comic, before he dies(The first and last love) and I think Arcee feels the same to him. In wiki
… it's say that it's an attraction to eachother. And I think in the future Bumblebee will fall in love with Arcee in TF: Prime, because I often see Bumblebee is always by her side, and in part 1 he somewhat quickly ran to Arcee's side when they were checking out the Energon site; and was visibly very worried when she collapsed of a touch of Dark Energon and in part 2 when Optimus told Arcee that she was in charge but she let Bulkhead be in charge instead of her then she go out patrol and take Bumblebee with her and in part 5 when she was hit by Megatron and flow out into the space, and the space bridge is going to explode Bumblebee hug Arcee and go in to the ground bridge when he walk out of the space bridge at the base he is carrying Arcee with him. PS. I love these two they are very cute, I wish they WILL BE a couple. PS2. I'm not that good in English so..sorry about some words that is spell it wrong. (MORE) 
