Girls want to be models, so they're ready to get on any dick that will get them a job in the modeling business. To suck or not to suck penises - such a question does not exist for them. Everyone sucks - just not everyone flaunts it. But not all of them are willing to let you work on your sweet pussy. At least the girls should be given time to get naked. There's no time to think about it. You got to ride the dick.
Brother and sister love each other. He likes to lick her pussy. She sucks his cock and jumps on it.