The 'official' plural second person pronoun in English is you. There are several ways in English to manufacture plural you, one of which is youse. According to etymonline.com youse is a : etymology - "youse" as a plural second person pronoun - English ...

Context Explanation

Youse, you'se, you-all, and several other forms have evolved, but none are universally accepted. "You people" is potentially derogatory and might best be avoided. We do have a Royal We.). Youse Guys is another variant...

Insight Material

though it's like "All y'all" which is talking to y'all but more y'alls than typical. (In Philadelphia proper, youse guys’ is probably used too!) Since you guys is colloquial, if you’re writing down the possessive of the word, you should use a spelling that reflects its pronunciation. If you’re wondering what to use in conversation, the answer is whatever you’ve been using all along. Probably directly deriving from Irish-Scottish original usage, but given other plurals such as youse, y'all, etc., feasibly just re-coined locally. Perhaps uptake was encouraged by a relatively high proportion of non-native speakers bothered by the fact that (unlike their languages) English had dumped the 2nd person singular/plural distinction.

Final Conclusion

Is that talking about the clitic ['s] for the possessive, or a contraction of is? In this case, both are fine. "Loving you's easy." "The dog that bit you's teeth were very yellow." Although it doesn't sound great because of the nonstandard word "youse" (plural "you"). I can confirm in N Ireland people often say youse and rarely say ye or yiz for the plural you - those 2 versions sound very Southern-Irish to Ulster ears.