How do I turn down a guys number I don’t know in my class without making it awkward?

A mutual friend in one of my classes who I’ve never talked to told my friend he was going to ask for me number Tuesday. I’ve never talked to him, from what I know he skips a lot and he’s pretty disruptive. My friend told him I’d say yes. I told her sure haphazardly not knowing she’d tell him but now I don’t want to anymore after thinking it over. How can I reject him without making it awkward when he sits like 2 seats away from me?

How do I turn down a guys number I don’t know in my class without making it awkward?
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