adjective

in keeping with good taste and propriety; polite and restrained.

Charlotte gave David a decorous kiss

proper,seemly,decent,becoming,befitting,tasteful,in good taste,tactful,correct,appropriate,suitable,fitting,fit,polite,well mannered,well behaved,genteel,refined,polished,well bred,dignified,respectable,courtly,civilized,formal,reserved,modest,demure,sedate,staid,gentlemanly,ladylike,comme il faut,mannerly,couth