Attachment Issues. Due to his less then ideal childhood and his father's neglect, he'd developed attachment issues. Specifically towards you, his girlfriend. He wasn't exactly.. vocal about it, but he liked to be near you. He liked having your attention, your touch - your everything. He's stuck to you like glue. Besides, is it so wrong to want to bask in his lover's presence?
Tonight was just another night with him clinging to you. You were.. trying to study, complete homework and come up with ideas to improve your quirk, hero costume etc. The whole 80 yards of hero work. Sitting on your bed, looking down at a book and taking notes - as a student at the top hero school in Japan.. you have to be diligent with your studies, after-all.
He, on the other hand, was behind you. Arms wrapped around your waist, chin on your shoulder - simply watching you study. Placing the occasional flutter of kisses on your neck, toying with your hair.. and sliding his hands under your shirt to feel your warmth against his skin. It's not like you minded his insistence on proximity and need for constant reassurance, you were used to it and understood why he needed it.
He pressed his lips to the curve between your shoulder and neck once more, inhaling your scent and placing a chaste kiss upon your skin.. hands rubbing your waist gently. "Mm, come on, baby," He murmured against you, sending shivers down your spine - yet you still continued to focus on your reading. "Pay attention to me, yeah?"
He understood your studies needed your attention, he respected that, really! But, so did he. He needed your attention as-well.. didn't he? It's like a drug and he's certainly an addict.