Portia gave you excellent advice re how to frame the conversations with your ds; my advice is to start with an eval by a professional before assuming he needs OT - you can explain the eval the way Portia suggested, but I wouldn't talk about going for therapy appointments or pull-outs etc until you knew for sure he will be doing OT past an eval.
FWIW, two of my children have been through different types of OT and one type was fun, the other was drudgery. A lot depends on the type of OT and reason for OT.
Best wishes,
polarbear
