what does "not compatible with condoms" mean?

My SO & I went to the store today & got VCF & the KY duration spray. We noticed the spray said it wasn't compatible with condoms but what exactly does that mean? I know some lube can cause condoms to break & I know he's worried about pregnancy. Would it be safe to use the spray with condoms & the VCF? I am currently ovulating, but if I used both? I just didn't know if mixing the condoms & spray would cause some kind of irritations or something? We would wait, but I fly out on Tuesday & we won't see each other for another few months.