Hi Mizel,
A multiple-entry visa will allow you to go in and out of the Schengen area just as you want in line with the validity and limitations indicated on the visa.
It's not normally allowed to stay in the Schengen Area for more than 90 days within a 180 day period so frequent travellers should check their passport stamps.

From the information you've shared you face no issues.
When my wife and I used to travel around the Schengen area we always carried supporting documentation as back up such as marriage certificate and booking docs with name and address etc. I'm not suggesting it's a requirement but sometimes immigration officers can be difficult.

You'll be fine, enjoy the trip