They behave differently around you
If a confident person is flirting with you, they may deliberately make you think they're interested. They may try to turn your conversation into something more interesting and entertaining. Their goal is to show you that they like you and build some excitement between you.
Conversely, if someone is shy, they may feel nervous around you. That doesn't mean they're not flirting, so watch out for more subtle signals. For example, more shy people tend to overthink, so if they try to get close to you or touch your hand/shoulder while talking, it could be a sign that they're flirting with you. In other cases, shy people have a hard time expressing their feelings and playing games, so they may pay attention to their eye contact to let you know they have a crush on you.
This means that whether they are confident or shy, there will be some changes in their behavior and the way they treat you.
They make it clear that they're available - and try to find out if you're available
If they try to make it clear right away that they're not chubby dating anyone and they lead the conversation to whether or not you're single, they're likely to start flirting with you and testing your reaction. They may also be trying to get a sense of how you feel about BBW dating and curvy dating relationships and whether you are a suitable BBW hookup partner.
They make fun of you
Some people flirt indirectly - they may tease you playfully or compliment you indirectly instead of doing so outright. It's a "safe" way to flirt, and some people use it in case the other person feels differently. It's also a way to make things more exciting and build an interesting chubby hookup relationship between the two of you.
Eye contact
This can be a little tricky. It is normal and polite for people to make eye contact with you. But if they are making more eye contact than usual, or if they are secretly looking at you, it could be a sign that they are flirting with you.
They care about you
When you're with a group of people, it's easier to see how focused they are. In this case, you can ask yourself a few questions: do they mainly look at you? Do they pay more attention to you when you're talking? Are they waiting for you when others are in front?
They find excuses to touch you
It varies from person to person - some people are just naturally sentimental. However, if a person's hands are reserved for themselves, but they are looking for an excuse to touch you, then this is a strong sign that they are flirting with you. It could be a hand on your arm while laughing, or a foot under the table.
Why don't you try it yourself?
Now that you have some ideas on how to flirt, you can use some of them to convey your interest in someone. Remember, the key to flirting is subtlety. Don't go overboard! This can be distasteful and make you seem overly enthusiastic.