Here's A-Rod talking about how he and J Lo have gone to multiple strip clubs together and spent thousands on dancers ... but he SWEARS it had nothing to do with getting freaky.
It was all for "research" ... and Alex says it was the BEST work he's ever done!
Of course, Lopez is starring in the upcoming stripper flick "Hustlers" -- and Alex told the guys on "The Breakfast Club" he was more than happy to help Jen get ready for the role.