'Jersey Shore' Star Ronnie Unsure Why Ex Came Over to Allegedly Attack

Ronnie Ortiz-Magro doesn't know why Jen Harley was allegedly snooping around his house before launching an attack with an eyeliner ... they're not dating and there was no invite. Sources close to Ronnie tell TMZ ... they are absolutely not...

'Jersey Shore' Star Ronnie Unsure Why Ex Came Over to Allegedly Attack
Ronnie Ortiz-Magro doesn't know why Jen Harley was allegedly snooping around his house before launching an attack with an eyeliner ... they're not dating and there was no invite. Sources close to Ronnie tell TMZ ... they are absolutely not back…