How to deal with catching feelings when you have a casual relationship?

Been talking to my ex again and I thought we was going to be serious and working on things. We had a convo about casual dating and I thought we both agreed we don't want each other to date someone else.

We talk all the time, between both of us working different schedules. Supposed to spend the weekend together as well. My ex calls during their lunch break, my ex was sleeping but woke up at 7am to talk to me before I started work.

Then I get a call in the evening, asking me what "we are we", then it's like I don't want to hurt your feelings. Me getting my feelings hurt, trying not to get upset on the phone, I said I thought we was just casual.

But I'm just confused, last week I got a text saying they liked me. The day before i was out for drinks, and I kind of feel like my ex might of thought it was a date. My was asking if I had been dating anyone else. Which came across in a jealous way 🤷🏼‍♀️.

I'm just hurt already and my ex hasn't actually dated anyone else yet. I did think before I could just keep it casual